The pressure of this contest has winnowed the field of serious candidates down to the three strongest — two Democrats and one Republican.

This pressure is revealing stress fractures in the ethical armor of surviving Democratic candidates Sens. Hillary Clinton and Barack Obama, as was evident this past weekend in the clashes of their surrogates on NBC’s “Meet the Press” and “Fox News Sunday.”

“Senator Schumer,” asked host Tim Russert, “if Barack Obama was ahead at the end of this primary season in elected delegates, states won and popular vote, should he be the nominee?”

Obama currently leads in all three of these categories. Nearly 800 convention “superdelegates,” mostly veteran political insiders able to override the will of voters, could become Ms. Clinton’s last best hope to become the Democratic standard-bearer.

“You need to know lots of details,” replied Schumer. “Did [Obama] win the other states 60-40, or did he win them 50.1 to 49.9? Is the popular vote overwhelming or is it not.”

“Senator Schumer,” pressed Russert, “Nancy Pelosi, the speaker of the House, said . . . it would be a problem for the [Democratic] party if the verdict would be something different than the public has decided. Do you agree?”

“There are good arguments on each side . . .,” sidestepped Schumer again. “This great epistemological, metaphysical issue,” Schumer continued, “no one thought about it three months ago. To me, it is not a great moral issue. The great moral issue is defeating George Bush, John McCain, and coming up with a way that we can do it . . .”

Florida and Michigan, continued Russert, violated delegate selection rules issued last August by Democratic National Committee Chairman Howard Dean that prohibited moving up the date of their delegate selection. If Florida and Michigan did this, Dean warned, both would suffer “a 100 percent loss of pledged and unpledged delegates.”

The Clinton campaign announced that it would “be signing the pledge to adhere to the DNC approved nominating calendar.”

But Clinton won victories in these penalized states where campaigning was prohibited and Obama’s name did not even appear on the Michigan ballot. In February 2008 the Clinton campaign declared that it would ask its delegates to vote to seat pro-Clinton Florida and Michigan delegations at the national convention and to count their votes.

“Senator Schumer,” Russert continued, “Senator Clinton said in October, ‘You know it’s clear this election they’re having in Michigan is not going to count for anything.’ Is that your position?”

“Well, let me say this, Tim,” said Sen. Schumer, who tap-danced away from any yes or no answer while urging compromise.

“One of the [compromise] plans being proposed,” said Russert, “is that there be caucuses in Michigan and Florida where both Obama and Clinton could compete. Would you support that?”

“Barack has done better in caucuses. Hillary has done better in primaries,” replied Schumer. “So I guess the Clinton campaign would say if we’re going to have something, you have to have primaries.”

“I can perceive what the Clinton strategy is now: to use these superdelegates to try to overcome the vote of elected delegates . . .,” said Durbin. “We certainly don’t accept these [Michigan and Florida] elections, because we agreed and Senator Clinton agreed that they wouldn’t count. And so now to count them is fundamentally unfair . . .

“If at the end of the day it appears [at the Democratic Convention] in Denver that something happened in a back room by the elite or the big shots or those well connected,” said Durbin, “that isn’t any good for the Democratic Party.”

“I think it would be an absolute disaster for the Democratic Party,” Wisconsin governor and Obama supporter Jim Doyle told Chris Wallace of Fox News, “for the superdelegates to undo the will of the people who have been selected in the primaries and in the caucuses and by the rules that were set out.”

If it were a private company, the Democratic Party might soon be required by Truth-in-Labeling laws to remove the word “Democratic” from its name.

Wallace asked Ohio governor and Clinton supporter Ted Strickland: “And what do you think . . . the reaction would be in the African-American community if the superdelegates, who are overwhelmingly white, were to go — to put Hillary Clinton in over Barack Obama?” Stickland never answered this question.

According to presumptive Republican nominee Sen. John McCain of Arizona, Barack Obama promised him that if they became their parties’ presidential candidates both would accept federal funding of their campaigns and the spending limits this requires to reduce the influence of special interests.

Democrats used to favor such limits when Republicans could raise and spent more campaign cash. In 2008 Obama has found it easier to raise political money than McCain has. So now, said McCain, Sen. Obama has reneged on his promise to use federal funds and is expected to outspend this limit by tens of millions of dollars.

But McCain, too, has sinned. Breaking promises and rules is what Americans find most angering about the millions of illegal aliens flooding into the United States — and about politicians such as Sen. McCain who, out of political fear or opportunism, have refused to stop this tidal wave or to enforce employment laws against these lawbreakers.

Our next president will be chosen from among three candidates, all of whom believe that playing by the rules and being ethical and honest is, in Sen. Schumer’s words, “not a great moral issue” if it gets in the way of winning.

In the American political system, our presidential races do more than give citizens the opportunity to caucus or cast ballots to choose our leaders.These races put would-be presidents through their paces, testing their character, ethics, honesty, skill, planning,...